This program is designed to investigate the major cases and mechanisms of pulmonary cancer in man through the study of lung cancer induced in animals. We are studying the carcinogenic potential of subfractions of air pollutents and cigarette smoke condensate with our system of wax-retaining pulmonary implants in rats. Currently, the aim is to determine what other factors, deficiencies et al. will affect responses. Secondly, we are investigating the critical factors responsible for fiber carcinogenesis in the lung and pleura which depend on structural configuration of the particles of fibers such as the gypsums, metal whiskers, talcs, asbestoses, and fibrous glasses and a variety of other durable fibers. An effort to develop a workable hypothesis on the primary effect of the fiber on cells is in progress. BIBLIOGRAPHIC REFERENCE: Stanton, M.F., Layard, M.W., Tegeris, A., Miller, E., May, M., and Kent, B.: The carcinogenicity of fibrous glass: Pleural response in the rat in relation to dimension. J. Natl. Cancer Inst. 58: 475-487, 1977.